SE ERS ey ee et ee IN Se ge ee Fe PE eg en ee ee Ma Pe Were tee eee 
Mere sr eee see 
igo] CURRENT LITERATURE 211 
known. Lidforss finds that organic acids, formic, acetic, succinic, lactic, 
tartaric, malic, etc., as well as amides, glucosides, and tannins, do not produce 
any undoubted effect upon the direction of growth of the tubes. Diastase, 
however, produces an almost immediate effect, and experiments show that it 
is the proteid constituent of the diastase which attracts the pollen tube. 
Further experiments show that carbohydrates and proteids are the substances 
which influence the direction of growth and indicate that the movement of 
the pollen tubes is for the purpose of securing nutrition. 
The pollen of most Liliacez: is more sensitive to mineral salts than 
Narcissus pollen, the same diastase preparation which attracts Narcissus 
pollen quickly killing the pollen of Fritillaria, but if the salts be dialyzed out 
the proteid exerts a strong influence upon Fritillaria pollen.— CuHas. J. 
CHAMBERLAIN. 
In AN ADDRESS before the Niederrheinische Gesellschaft fiir Natur und 
Heilkunde zu Bonn,® Dr. F. Noll? makes a suggestion which is likely to prove 
fruitful, because it not only groups together some previously isolated facts, but 
—_ likely to be the starting point of further investigations. He has been led 
to believe that the form of the plant body itself is a source of both orienting 
a stimuli. As evidence of this he appeals to the fact that in 
aoe vesiaes the concave side of roots remains entirely free of lateral 
ie at se are limited to the convex side; or, if they appear at all upon 
nks, they bend more or less sharply toward the convex side. 
alae have been observed in all the plants studied, including 
are Naa all the great groups which develop roots. fe 4 
Pelagia, — Noll correlates Wiesner’s ‘exotrophy,” a pics nh 
fanks i ee, ereby the growth of external members or their externa 
Picuously promoted as compared with that of corresponding 
Members 5 : P 
Polarity have a 
fields a : 
iso need exploring from this new point of departure.—C. RB; 
is “oskiigay by A. C. Hill that the hydrolysis of maltose by maltase 
tose from 9] process and that this enzyme is also capable of forming mal- 
seems to be supported by the results of M. Cremers 
- finds that the glycogen-free expressed extract of yeast is 
cing glycogen in a 30 per cent. solution of fructose, which 1s 
eg d. Sitzungsber. d. Niederrhein.. Gesells. 1900; Sitzung von Jan. 
“apable of produ 
*Sep. Abd 
"51900. pp, 
Noll’ : 
withichefticke 1 researches are announced to be published in Thiel’s pa 
nig € Jahrbiicher early in this year. 
ans. Chemical Soc. 1898 : 634-658. 
ha 
Berichte 
© d. deutsch, chem. Gesells. 1899 : 2062-2064. 
